Multi-channel chemical transport bus with bus-associated sensors for microfluidic and other applications

ABSTRACT

A controllable multiple-channel chemical transport bus routes and transports fluids, gasses, aerosols, slurries and the like within a larger system. The system and methods are applicable for use in Lab-on-a-Chip (LoC) technology, and can be useful in the implementation of reconfigurable LoC devices. Routes through the bus are determined by control signals and/or sequences of control signals issued under algorithmic control. Several independent flows may occur simultaneously. Adaptations of Clos, Banyan, and other related multi-stage switching architectures in the flow topology can be supported. Sensors are placed at various locations along bus path segments. Information gathered by the sensors can be used for one or more of controlling measured flows, clearing operations, cleaning operations, and control of the timing flow transport. The sensors can be of one or more types such as presence sensors, flow sensors, pressure sensors, temperature sensors, conductivity sensors, optical sensors, ion sensors, and affinity sensors.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/328,716, now U.S. Pat. No. 8,032,258, filed on Dec. 4, 2008 andissued on Oct. 4, 2011, and pursuant to 35 U.S.C. Section 119(e),claiming benefit of priority from provisional patent application Ser.No. 61/005,429, filed Dec. 4, 2007, the contents of which are herebyincorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION Field of Invention

The present invention generally relates to the controllable routing andtransport of fluids, gasses, and slurries, and in particular, tomultiple input/multiple output chemical transport.

SUMMARY OF THE INVENTION

Features and advantages of the invention will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

One embodiment includes a system for implementing anelectrically-operated multi-channel chemical transport bus. This systemincludes a plurality of chemical flow ports, each chemical flow portconnected to at least one associated first electrically-operated valveand further in chemical flow communication with at least one associatedsecond electrically-operated valve; a first chemical flow bus lineconnecting with each first electrically-operated valves respectfullyassociated with each chemical flow port from the plurality of chemicalflow ports, each connection made at an associated tap in the firstchemical flow bus line, the first chemical flow bus line furthercomprising a first pair of additional electrically-operated valves, oneon either side of at least one tap of the associated tap in the firstchemical flow bus line; a second chemical flow bus line connecting witheach second electrically-operated valves respectfully associated witheach chemical flow port from the plurality of chemical flow ports, eachconnection made at an associated tap in the second chemical flow busline, the second chemical flow bus line further comprising a second pairof additional electrically-operated valves, one on either side of atleast one tap of the associated tap in the second chemical flow busline; and a controller for selectively controlling the operation of eachof the electrically-operated valves, the controller controllingcommunications with each of the electrically-operated valves. Thecontroller further controls the electrically-operated valves to: preventchemical flows between a first and second chemical flow ports of theplurality of chemical flow ports; transport chemical flows between afirst and second chemical flow ports of the plurality of chemical flowports, wherein the transported chemical flow does not extend into thechemical flow bus line beyond at least the first or the second pair ofadditional valves; and again prevent chemical flows between a first andsecond chemical flow ports of the plurality of chemical flow ports.

These and other embodiments will also become readily apparent to thoseskilled in the art from the following detailed description of theembodiments having reference to the attached figures, the invention notbeing limited to any particular embodiment disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of the presentinvention will become more apparent upon consideration of the followingdescription of preferred embodiments, taken in conjunction with theaccompanying drawing figures.

FIG. 1 a shows a first illustrative example of a unidirectional flowMulti-channel Chemical Transport Bus for use in controlledunidirectional transfer of chemical substances from a plurality oforiginating sources outside of a system to a plurality of destinationsinks within the system.

FIG. 1 b shows a second illustrative example of a unidirectional flowMulti-channel Chemical Transport Bus similar to that depicted in FIG. 1a but configured to provide transport flows in the opposite direction.

FIG. 2 a shows a third illustrative example of a unidirectional flowMulti-channel Chemical Transport Bus where some elements within thesystem act as sources while other elements within the system act assinks.

FIG. 2 b shows an example of a Multi-channel Chemical Transport Buswherein devices, subsystems, or other elements within the system act asboth sources and as sinks.

FIG. 3 a shows an exemplary arrangement wherein a Multi-channel ChemicalTransport Bus interfaces with some elements which are only sources,other elements which are only sinks, and yet other elements which mayfreely act as sources or sinks and in some embodiments connect to thebus with bidirectional paths.

FIG. 3 b shows an exemplary variation of the arrangement of FIG. 3 aaugmented to include sinks and/or sources outside the system.

FIG. 3 c shows an exemplary variation of the arrangement of FIG. 3 baugmented to include bidirectional paths to elements outside the system.

FIG. 4 shows a simple exemplary embodiment of a closed system (such asthat depicted in the exemplary arrangements depicted FIG. 2 a, 2 b, or 3a), here realized by a plurality of tapped or branching transport pathsand a plurality of on/off valves.

FIG. 5 a depicts an exemplary configuration that can result fromselected open and closed state assignment made to valves within anexemplary eight device embodiment of FIG. 4 wherein three pairs ofdevices are interconnected and two devices are isolated.

FIG. 5 b depicts an exemplary configuration that can result fromselected open and closed state assignment made to valves within anexemplary eight device embodiment of FIG. 4 comprising fan-out andmixing attributes.

FIG. 5 c depicts an exemplary configuration that can result fromselected open and closed state assignment made to valves within anexemplary eight device embodiment of FIG. 4 comprising distributionvalve and selection valve attributes.

FIG. 6 a depicts an example of a persistent-state control signal used tocontrol a controllable valve. In some embodiments the driver may beomitted.

FIG. 6 b depicts an example of a state-transition control signal used tocontrol a controllable valve. In some embodiments the driver may beomitted.

FIG. 6 c depicts exemplary use of a flip-flop function to convert anincoming state-transition control signal into a persistent-state signalto maintain the state of a controllable valve. In some embodiments thedriver may be omitted.

FIG. 6 d depicts exemplary use of a one-shot function to convert anincoming persistent-state control signal into a state-transition signalto change the state of a controllable valve. In some embodiments thedriver may be omitted.

FIG. 7 a depicts a first exemplary arrangement for providing controlsignals to a collection of k controllable valves via a controllingprocessor.

FIG. 7 b depicts a second exemplary arrangement for providing controlsignals to a collection of k controllable valves via a demultiplexerthat demultiplexes an incoming control signal.

FIG. 7 c depicts a third exemplary arrangement for providing controlsignals to a collection of k controllable valves via an addressablelatch responsive to an incoming control signal.

FIG. 7 d depicts a fourth exemplary arrangement for providing controlsignals to a collection of k controllable valves via a local controllingprocessor responsive to an incoming control signal and/or othercommunications.

FIG. 7 e shows an exemplary arrangement wherein two or more instances ofthe exemplary control signal arrangements of FIGS. 7 b-7 d may beincorporated into a larger-scale control signal architecture.

FIG. 7 f shows an exemplary variation of the arrangement of FIG. 7 ewhere the control processor is replaced by a local controlling processorprovided with an external communications path that may connect withanother peer, superior, or subordinate processor, directly or viaanother communications bus.

FIG. 7 g shows an exemplary variation of the arrangement of FIG. 7 ewhere the control processor is not provided and the local control signalsources (such as local controlling processors depicted FIG. 7 d) maycommunicate amongst themselves.

FIG. 7 h shows an exemplary variation of the arrangements of FIG. 7 fand FIG. 7 g wherein the local controlling processor of FIG. 7 e isreplaced by a bus interface provided with an external communicationspath that may connect with another peer, superior, or subordinateprocessor, directly or via another communications bus.

FIG. 7 i shows an exemplary arrangement wherein two or more instances ofthe arrangement of FIG. 7 f are connected with an additional sharedsignal bus that is also connected to a global control processor. In someembodiments the shared signal bus may also provide control signals toand/or exchange other communications with other controlled devicesand/or processors.

FIG. 7 j shows an exemplary variation on the arrangement of FIG. 7 iwherein the global control processor is replaced by a global controllingprocessor provided with an external communications path that may connectwith another peer, superior, or subordinate processor, directly or viaanother communications bus.

FIG. 7 k shows an exemplary variation on the arrangement of FIG. 7 jwhere the global controlling processor is replaced by a bus interfaceprovided with an external communications path that may connect withanother peer, superior, or subordinate processor, directly or viaanother communications bus.

FIG. 8 a shows an exemplary open system embodiment employing the samebasic types of components and architectures as that of the closed systemembodiment of FIG. 4 but adding additional external paths to the buslines to provide inputs and outputs of chemical substances to and fromthe larger associated system. Additionally, ports that would otherwiseconnect with system-internal devices may be used as inputs and outputs.

FIG. 8 b shows a variation of FIG. 8 a where only some of the bus linesare provided with external paths while others no such external paths.

FIG. 9 a depicts an exemplary situation involving incoming and outgoingflow invoking seepage, splattering osmosis, pressure gradients, and/orother leaking and leeching processes (as shown by the dashed lines) ateither end of the routed flow and into the vestibules paths of othervalves.

FIG. 9 b illustrates how the introduction of additional on/off“localization” valves to localize leakage and leeching illustrated inFIG. 9 a to a smaller span.

FIG. 9 c shows a systematic repetitive placement of the numerous on/offvalves throughout the bus lines to localize leaking and leeching revealsfunctionally redundant valves at either end of each bus line.

FIG. 9 d shows a simplification of the arrangement of FIG. 9 c wherefunctionally redundant valves at either end of each bus line have beenremoved.

FIGS. 10 a-10 d show exemplary usage of the arrangement of FIG. 9 d toprovide a sequence of different flow paths, and also illustrate that agiven valve can potentially being reused in the transport of typicallydifferent chemical substances, raising issue of single-purpose use,clearing and cleaning.

FIG. 11 a depicts with an extra dedicated bus line linked to each deviceport with an individually associated single-pole double-throw (“3-way”)valve for injecting clearing or cleaning material(s) into an attacheddevice.

FIG. 11 b shows exemplary flow through this dedicated bus line.

FIG. 12 a depicts a similar extra dedicated bus line linked to eachdevice port with an individually associated single-pole double-throwvalve for evacuating remnant substances, clearing, and/or cleaningmaterial(s) from an attached device.

FIG. 12 b shows exemplary flow through this dedicated bus line.

FIG. 13 a illustrates some exemplary placements of sensors, representedby dashed squares, at various locations along the bus line segmentsbetween consecutive taps and port paths.

FIG. 13 b depicts other sensor placements on either proximate side of aon a bus line tap.

FIG. 14 depicts an idealized continuous flow between two devices.

FIG. 15 a shows a short-duration flow segment, or burst, of an exemplaryliquid substance or material in the process of being transported from asource device.

FIG. 15 b shows the exemplary liquid substance or material presented nowtraveling through a bus segment.

FIG. 15 c shows the exemplary liquid substance or material now in thelast stages of transport to a sink device.

FIGS. 15 d-15 e illustrate another embodiment wherein once the exemplaryliquid substance or material is sufficiently localized within the bussegment, the valve associated with the source port is closed and apropellant gas may be applied from another source port.

FIG. 16 a shows an exemplary closely-spaced sequence of bursts of thesame liquid substance or material.

FIG. 16 b depicts an alternate next step of this exemplary sequencewherein the destination port valve on the bus closes, allowing the flowto be directed to another destination via a now opened valve on the busline while a burst segment destined for the original destination butremaining in-line can be delivered by introducing a propelling gas fromanother source port via another bus line and associated open valves.

FIG. 17 shows stuttered bursts of liquid substance or material beingtransported.

FIG. 18 a shows a liquid substance or material burst (Burst #1)introduced by Device 2.

FIG. 18 b shows Burst #1 continues moved into the top bus line.

FIG. 18 c shows both bursts traveling through the bus line.

FIG. 18 d shows Burst #1 now about to arrive at destination Device 4 andBurst #2 having already traversed several now-closed valves, confiningit.

FIG. 18 e shows Burst #2 arriving at its destination, allowed or drivento travel by venting or propelling gas provided by Device m−1 viaseveral now opened valves.

FIG. 19 a shows a device port bus column where the on/off valves havebeen replaced with a cascade of SPDT valves.

FIG. 19 b shows an exemplary gated path through the port bus column ofFIG. 19 a.

FIG. 19 c shows when the arrangement shown in FIG. 19 a is constructedin the opposite manner that can be used as a distribution valve readilyamenable to clearing and cleaning.

FIG. 19 d shows an exemplary gated path through the arrangement of FIG.19 c.

FIG. 20 a depicts an exemplary alternate realization of a Multi-channelChemical Transport Bus employing the valve cascade arrangement of FIG.19 a as the device port bus column.

FIG. 20 b depicts an exemplary alternate realization of a Multi-channelChemical Transport Bus employing the valve cascade arrangement of FIG.19 c as the device port bus column.

FIG. 21 a depicts an exemplary expanded arrangement where each port isprovided with a SDPT valve, the SDPT valve selecting between what wouldotherwise be two separate ports of the same Multi-channel ChemicalTransport Bus.

FIG. 21 b shows a corresponding adaptation of FIG. 21 a where the SDPTvalves have been replaced with k-port mutually-exclusive selection ordistribution valves where each of the k ports selects among what wouldotherwise be k separate ports of the same Multi-channel ChemicalTransport Bus.

FIG. 22 a shows the arrangement of FIG. 21 a where the two ports of theSPDT valve are connected to what would otherwise be the output ports oftwo separate Multi-channel Chemical Transport Busses.

FIG. 22 b shows an arrangement of FIG. 21 b where each of the k portsconnected to what would otherwise be the output ports of k separateMulti-channel Chemical Transport Busses.

FIG. 23 shows an exemplary implementation of FIG. 22 b using only on/offvalves.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following detailed description, reference is made to theaccompanying drawing figures which form a part hereof, and which show byway of illustration specific embodiments of the invention. It is to beunderstood by those of ordinary skill in this technological field thatother embodiments may be utilized, and structural, electrical, as wellas procedural changes may be made without departing from the scope ofthe present invention. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or similarparts.

In microprocessor and other computer-based systems, an electrical bus,computer bus, data bus, etc. (often referred to herein as simply a bus),provides an interface where a plurality of associated or attacheddevices are able to share a common transaction environment. Such a busis typically used to transfer data signals, control signals, and poweramong attached electrical and information devices.

In some applications, the bus provides a mechanism for adding andremoving component subsystems. In these as well as other applications,the bus may be used to distribute data, control, and/or power to varioussubsystems within a larger system. Of the latter, a bus may be usedwithin a circuit board or within an integrated circuit.

Although there are distinct differences and many special considerationsand provisions that must be provided, various embodiments of the presentinvention adapt this concept of a bus to provide methods and systems forthe controlled transfer of fluids, gases, slurries, and the like withina larger system such as a micro-fluidic Lab-on-a-Chip (LoC) device,chemical instrumentation package, etc.

More specifically, such embodiments are directed to a variety of methodsand systems relevant to the creation of sophisticated and/orhigh-performance chemical transport buses such as that which may be usedin LoC devices, larger-scale chemical systems, and devices that emulatethese. Such embodiments may be very useful in the implementation ofsoftware-reconfigurable chemical process systems, such as thosedescribed in U.S. patent application Ser. No. 11/946,678, filed Nov. 28,2007. Moreover, these embodiments may additionally be very useful in theimplementation software-controlled physical emulation systems andmethods such as those taught in a companion provisional patentapplication Ser. No. 61/005,369, filed Dec. 4, 2007.

In view of the differences and many special considerations andprovisions that are typically provided in order to achieve a chemicaltransport bus providing controlled transfer of fluids, gases, slurries,and the like within a larger system, the basic principles of anelectrical or optical signal bus, timing bus, and/or electrical poweringbus will not always be directly adopted. Rather, a chemical transportbus may be constructed using alternative concepts and principles.

Basic Frameworks for a Controllable Multi-Channel Chemical Transport Bus

FIG. 1 a shows a first illustrative example of a unidirectional flowMulti-channel Chemical Transport Bus (MCTB) 101 for use in controlledunidirectional transfer of chemical substances from a plurality 111 oforigin sources (depicted in the figure as a vertical column of smallcircles, each small circle representing an individual source within theplurality 111 of sources) that are interfaced outside of a system 201.Chemical substances provided by the sources are transferred to aplurality 121 of destination sinks (depicted in the horizontal row ofsmall circles, each small circle representing an individual sink withinthe plurality 121 of sinks) within the system 201. The individual sinks121 making up the plurality 121 of sinks may be local devices orsubsystems included in the system 100. In principle, the chemicalsubstances may include one or more of various types of liquids, gases,slurries, aerosols, as well as mixtures of these.

In this example, each of the sources comprised by the plurality 111 ofsources are typically in some manner distinct from one another and therouting of transport is controlled by one or more control signal(s) 151.The control signals 151 may be of one or more types, for exampleelectrical, optical, pneumatic, chemical, acoustic, magnetic,radio-frequency electromagnetic, etc., as may be advantageous in anapplication or implementation. The control signals may be primitiveon-off, pulse-width modulated, analog, etc., and individual routingcontrols may be rendered with various types of signal and interfaceorganizations (for example multiplexed, space-division, ACSII, I²C,etc.) as may be advantageous in an application or implementation.

In some embodiments it may be helpful to limit cross-contaminationwithin the Multi-channel Chemical Transport Bus (MCTB) 101 chemicalsubstances provided by the plurality 111 of sources. In otherembodiments, this cross-contamination condition may be more relaxed,particularly during transitions where first one and later another of thechemical substances provided by the plurality 111 of sources areselectively provided to the same individual sink from the plurality ofsinks (destinations) 121. In other embodiments, the Multi-channelChemical Transport Bus (MCTB) 101 may internally mix two or more of thechemical substances provided by the sources 111. In these embodiments,such mixing may be realized as simple on-off flow control, pulse-widthmodulated on-off flow control, proportional flow control, etc. as may beadvantageous in an application or implementation. Further, such mixingmay be sequenced or involve at least some time interval of simultaneousflow.

FIG. 1 b shows a second example of a unidirectional flow Multi-channelChemical Transport Bus (MCTB) 102 incorporated into a system 202 similarto that depicted in FIG. 1 a, but herein is configured to provide allthe depicted transport flows in the opposite direction. In this example,chemical substances can originate from any of a plurality 112 of sourceswithin the system and transferred, as directed by control signals 152,to any of a plurality 122 of sinks or paths outside the system 202.

FIG. 2 a shows a third example of a unidirectional flow Multi-channelChemical Transport Bus (MCTB) 103, directed by control signals 153,wherein some devices, subsystems, or other elements within the system203 act as sources 113 while other devices, subsystems, or otherelements within the system 203 act as sinks 123. As there are no sourcesand/or sinks outside the system 203, the arrangement depicted in FIG. 2a will be referred to as closed. In contrast, each of the arrangementsof FIGS. 1 a and 1 b in that they each involve sources and/or sinksoutside the system 203, will be referred to as open.

FIG. 2 b shows an example of a Multi-channel Chemical Transport Bus(MCTB) 104, directed by control signals 154, wherein devices,subsystems, or other elements 144 within the system 204 act as bothsources and as sinks. In some embodiments the path linking the elements144 with the Multi-channel Chemical Transport Bus (MCTB) 104 can bebidirectional. As there are no sources and/or sinks outside the system204, the arrangement depicted in FIG. 2 b is closed.

FIG. 3 a shows another example arrangement wherein the Multi-channelChemical Transport Bus (MCTB) 105, directed by control signals 155,interfaces with some elements 115 which are only sources, other elements125 which are only sinks, and yet other elements 145 which may freelyact as sources or sinks and in some embodiments connect to the bus withbidirectional paths. It is clear to one skilled in the art that manyvariations of this exist wherein one system internal sources 115 orsystem internal sinks 125 may be omitted from the exemplaryconfiguration depicted in FIG. 3 a. Note that since there are no sourcesand/or sinks outside the system 205, the arrangement depicted in FIG. 3a is closed.

FIG. 3 b shows an exemplary variation of the arrangement of FIG. 3 awhich is augmented to include external sources 116 and external sinks126 outside a system 206 as well as internal sources 115, internal sinks125, and internal bidirectional elements 145 within the system 206. Itis clear to one skilled in the art that many variations of this existwherein one or more of the depicted system internal sources 115, systeminternal sinks 125, system internal bidirectional elements 145, systemexternal sources 116, and/or system external sinks 126 may be omittedfrom the exemplary configuration depicted in FIG. 3 b. Note that thearrangement depicted in FIG. 3 b as shown is an open system, and anyvariations having at least one of external sources 116, external sinks126 bidirectional paths 146 to elements outside the system 206 are alsoopen system.

As shown in FIG. 3 c, bidirectional paths 146 to elements outside thesystem may also be provided in a similar fashion. It is clear to oneskilled in the art that many variations of this exist wherein one ormore of the depicted system internal sources 115, system internal sinks125, system internal bidirectional elements 145, system external sources116, and/or system external sinks 126 may be omitted from the exemplaryconfiguration depicted in FIG. 3 c. Note that the arrangement depictedin FIG. 3 c as shown is an open system, and any variations having atleast one of external sources 116, external sinks 126 bidirectionalpaths 146 to elements outside the system 207 are also open system.

Exemplary Embodiments and Capabilities of a Controllable Closed-SystemMulti-Channel Chemical Transport Bus

FIG. 4 shows a simple exemplary embodiment of a closed Multi-channelChemical Transport Bus arrangement such as that depicted in theexemplary arrangements depicted FIG. 2 a, 2 b, or 3 a. The embodimenthere is realized by a plurality of tapped or branching transport paths(m paths vertically 401.1-401.m and n paths horizontally 410.1-410.n),to be referred to as bus lines, and a plurality of n×m on/off valves401.1-401.n.m. The of n×m on/off valves 401.1.1-401.n.m may becontrolled by control signals such as those 153, 154, 155 of FIG. 2 a, 2b, or 3 a.

The example of FIG. 4 consists of m devices connecting to ports405.1-405.m, each port terminating an associated tapped or branchingpath 401.1-401.m, wherein a port terminating the tapped or branchingpath 400.1 connects to Device 1, the port terminating the tapped orbranching path 400.2 connects to Device 2 and so on, wherein the portterminating the tapped or branching path 401.m connects to Device m. Inthat proper operation of a pair of selected valves sharing the samehorizontally tapped or branching path 410.1-410.n will allow any of thedevices in the system to exchange chemical substances with any otherdevice in the system, FIG. 4 is may be realized using any of thearrangements depicted in FIG. 2 a, 2 b, or 3 a.

The embodiment of FIG. 4 can be used to selectively interconnect theports 405.1-405.m among one another responsive to the aforementionedcontrol signals. This subsequently provides a controllable feature forselectively interconnecting the m devices to permit the exchange ofchemical substances among the m devices. For example consider a systemsuch as that depicted in any of FIG. 2 a, 2 b, or 3 a with m=8.Responsive to control signals, various configurations can be obtained.Three examples are depicted in FIGS. 5 a-5 c, to be discussed next

In a first example, consider the arrangement of FIG. 4 wherein, inresponse to control signals, the following valves are open:

400.1.1

400.1.2

400.2.3

400.2.4

400.3.5

400.3.6

and all other valves are closed. The result is the configurationdepicted in FIG. 5 a wherein Device 1 is connected with Device 2, Device3 is connected with Device 4, Device 5 is connected with Device 6, andDevice 7 and Device 8 are not connected to any other of the devices.More generally, in this modality, the Multi-channel Chemical TransportBus provides a controllable “point-to-point interconnection” operation.Depending on the nature and internal state of the individual devices,the chemical substance flows supported by the interconnections may beunidirectional in either direction or may be bidirectional.

In a second example, consider the arrangement of FIG. 4 wherein, inresponse to control signals, the following valves are open:

400.1.1

400.1.2

400.1.3

400.2.4

400.2.5

400.3.6

400.3.7

400.3.8

and all other valves are closed. The result is the configurationdepicted in FIG. 5 b wherein Device 1 is connected with both Device 2and Device 3, Device 4 is connected with Device 5, and Device 8 isconnected with both Device 6 and Device 7. As with the previous example,the chemical substance flows supported by the interconnections may beunidirectional in either direction or may be bidirectional. Foradditional points of illustration, the example depicted in FIG. 5 b hasflow directions as indicted by the arrows shown. Here, then, the flowfrom Device 1 is simultaneously directed to both Device 2 and Device 3;this situation creates a “fan-out” operation within the Multi-channelChemical Transport Bus. Additionally, the flow from Device 6 and Device7 are simultaneously directed to Device 8; this situation creates a“mixing” operation within the Multi-channel Chemical Transport Bus(although in microfludic flows formal diffusion-type mixing may notdirectly occur without additional provisions due to laminar phenomenaintrinsic to most types of microchannels).

In a third example, consider the arrangement of FIG. 4 wherein, inresponse to control signals, the following first group of valves areeach open:

400.1.1

400.2.5,

individual valves in the following second group may be opened mutuallyexclusively in response to control signals:

400.1.2

400.1.3

400.1.4,

and individual valves in the following third group may be openedmutually exclusively in response to control signals:

400.2.6

400.2.7

400.2.8

and all other valves are closed. As with the previous example, thechemical substance flows supported by the interconnections may beunidirectional in either direction or may be bidirectional. Foradditional points of illustration, the example depicted in FIG. 5 c hasflow directions as indicted by the arrows shown. The result is anarrangement wherein, responsive to controls signals, the flow fromDevice 1 can be distributed to any of Device 2, Device 3, or Device 4;this situation creates a controllable “distribution valve” operationwithin the Multi-channel Chemical Transport Bus. Additionally, theresult also includes an arrangement wherein, responsive to controlssignals, the flow from any of Device 6, Device 7, or Device 8 can beselected for flow into Device 5; this situation creates a controllable“selection valve” operation within the Multi-channel Chemical TransportBus.

Thus, the Multi-channel Chemical Transport Bus embodiment provided inFIG. 4 can provide the following five controllable operations onchemical substance transport among the eight devices:

Controlled point-to-point interconnection operation,

Controlled fan-out operation,

Controlled mixing operation,

Controlled selection valve operation,

Controlled distribution valve operation.

A number of further extensions and refinements of the exemplary systemsand methods described above are provided later in the description.Attention is directed to classification remarks made relating to thefive exemplary operations described above.

The first of these classification remarks concern matters ofdistinguishing initial configuration, modal operation, andreconfiguration:

-   -   In many situations and applications, one or more of instances of        one or more of the five types of Multi-channel Chemical        Transport Bus operations listed above may be enacted prior to        the operation of the associated larger system. This enactment        establishes an initial configuration of the associated larger        system.    -   In many situations and applications, one or more of instances of        one or more of the last two types of Multi-channel Chemical        Transport Bus operations listed above may be enacted during        operation of the associated larger system. These enactments may        be viewed as modal operation of the associated larger system        within a previously established initial configuration.    -   In some situations and applications, one or more of instances of        one or more of the first three types of Multi-channel Chemical        Transport Bus operations listed above may be enacted during        operation of the associated larger system.        -   In some contexts, particularly where minor variations            result, these enactments may, too, be viewed as modal            operation of the associated larger system.        -   In other contexts, particularly where significant variations            or fundamental structural changes result, these enactments            may instead be viewed as a reconfiguration of the associated            larger system.

For example, should the connections between any one or more of theinterconnect pairs of Devices 1-6 provided by the Multi-channel ChemicalTransport Bus in FIG. 5 a be interrupted during of the operation ofassociated larger system, the situation may be viewed as modal operationof the associated larger system. In contrast, should the interconnectionand isolations of Devices 1-8 provided by the Multi-channel ChemicalTransport Bus depicted in FIG. 5 a be changed to become those depictedin FIG. 5 b or 5 c, the situation may be viewed as a reconfiguration ofthe associated larger system.

The second of these classification remarks concern matters ofdistinguishing selection versus mixing and distinguishing distributionversus fan-out:

-   -   A “controlled selection valve operation” involves at most one        valve open at one time from among a group of valves sharing a        tapped or branched path. A “controlled mixing operation”        involves at least two or more valves open at one time from among        a group of valves sharing a tapped or branched path.    -   A “controlled distribution valve operation” involves at most one        valve open at one time from among a group of valves sharing a        tapped or branched path. A “controlled mixing operation”        involves at least two or more valves open at one time from among        a group of valves sharing a tapped or branched path.

Next, it is noted that the number n bus lines 410.1-410.n determines thenumber of simultaneously available linkages available between devices.In reference to the earlier examples depicted in FIGS. 5 a-5 c:

-   -   The configuration depicted in FIG. 5 a requires three        interconnections, so n must be at least 3 in order to support        this configuration. If n=3, then it is typically not possible to        additionally connect Devices 7 and 8 as this would usually        require four bus lines 410.1-410.4;    -   The configuration depicted in FIG. 5 b requires three        interconnections, so n must be at least 3 in order to support        this configuration.    -   The configuration depicted in FIG. 5 c requires two        interconnections, so n must be at least 2 in order to support        this configuration.

For realizing a particular configuration, the on/off state of individualvalves may be fixed (so as to render a particular configuration) for anepoch of time or may vary over time (so as to change modes of operationor in a reconfiguration action transforming the larger system from oneconfiguration to another). Typically the transition response time andsettling time of the individual valves are desired to be as rapid aspossible. Between transitions, the on/off state of individual valveswill remain unchanged, often for relatively long periods of time.

Persistent-State and State-Transition Control

In some embodiments, the on/off state of individual valves is determinedby whether ongoing energy is applied to the valve. For example, manytypes of solenoid valve (and their microfluidic equivalents) require anelectric current to keep the valve in one state, and when the electriccurrent stops the valve attains the opposite state. More specifically, a“normally closed” valve permits flow through it only when an electriccurrent is applied, while a “normally open” valve blocks flow through itonly when an electric current is applied. In many such embodimentsemploying these types of valves, current must be applied to at leastsome valves in order for the Multi-channel Chemical Transport Bus to beable to implement at least some, if not all, of the possibleconfigurations (i.e., such as those depicted in FIGS. 5 a-5 c). Someimplications include:

-   -   If all valves used in the realization of a Multi-channel        Chemical Transport Bus are effectively “normally closed,” then        in the absence of power no non-trivial (i.e., everything        isolated) configurations can typically be realized. In some        applications this behavior may be advantageous, while in other        applications this behavior can introduce additional design        considerations or design problems.    -   In order for valve settings to be maintained, outside means (for        example electrical logic circuitry such as flip-flops or other        form of memory) must typically be provided to maintain valve        state over time.

In other embodiments, individual valves used in the realization of aMulti-channel Chemical Transport Bus may be “bi-stable” or have othermechanical means or inherent attributes that allow a valve state to beretained in the absence of applied electrical current or other forms ofenergy or power. In such systems, electrical current or other forms ofenergy or power may be used to cause a valve element to change state.Use of these types of valve elements in realizing a Multi-channelChemical Transport Bus with an approach such as that depicted in FIG. 4allows a given configuration specified by control signals to bemechanically retained after removal of power to the larger associatedsystem.

It is noted that a Multi-channel Chemical Transport Bus may beimplemented with other types of valve elements. Various examplerealizations of a Multi-channel Chemical Transport Bus employing anentirely different type of valve element will be provided later (forexample, those to be described in conjunction with FIGS. 19 a-19 d), forexample those of FIGS. 20 a-20 b.

Prior to this, attention is first directed to control signals,interfacing a Multi-channel Chemical Transport Bus structure such asthat of FIG. 4 to external sources and sinks, and the management ofwaste and contamination within the bus lines comprised by theMulti-channel Chemical Transport Bus.

Attention is now directed to control signals that may be used to controla Multi-channel Chemical Transport Bus realization. As mentionedearlier, such control signals may include one or more types (for exampleelectrical, optical, pneumatic, chemical, acoustic, magnetic,radio-frequency electromagnetic, etc.) as may be advantageous in anapplication or implementation. Further, control signals may be primitiveon-off, pulse-width modulated, analog, etc., and individual routingcontrols may be rendered with various types of signal and interfaceorganizations (for example multiplexed, space-division, ACSII, I²C,etc.) as may be advantageous in an application or implementation.Additionally, control signals may be of two characters:

-   -   Persistent-state control signals which specify the instantaneous        state for a target valve, or    -   State-transition control signals which specify changes of state        for a target valve.

As an example of a persistent-state control signal, a control signalvalue associated with a logical “1” (for example, +V_(DD) in CMOS or +5volts in TTL) may cause a particular valve to open and remain open onlyas long as that control signal remains in the logical “1” state. Such asituation is shown by the arrangement depicted in FIG. 6 a. Here anincoming persistent-state control signal 601 may be provided to a driver631 which may convert, regenerate, and/or isolate the control signalinto power or energy 641 used to maintain the state of a controllablevalve 651. In some situations, the persistent-state control signal 601itself may be such that it can directly provide power or energy 641 todirectly maintain the state of a controllable valve 651; in this casethe driver 631 may be omitted. Additionally, should the provided controlsignal intended to control the valve 653 not be compatible with the typeof input signal needed for the flip-flop 613 (for example the providedcontrol signal may be optical while the flip-flop 613 may requirestate-transition control signal 603 to be electrical), a conversionoperation (not pictured) may be provided in order to produce astate-transition control signal 603 compatible with the input to theflip-flop 613.

As an example of a state-transition control signal, a control signalpulse or message of one type may cause a particular valve to open andremain open and a control signal pulse or message of another type maycause a particular valve to close and remain closed. Such a situation isshown by the arrangement depicted in FIG. 6 b. Here an incomingstate-transition control signal 602 may be provided to a driver 632which may convert, regenerate, and/or isolate the control signal intopower or energy 642 used to change the state of a controllable valve652. In some situations, the persistent-state control signal 602 itselfmay be such that it can directly provide power or energy 642 to directlymaintain the state of a controllable valve 652; in this case the driver632 may be omitted. Additionally, should the provided control signalintended to control the valve 653 not be compatible with the type ofinput signal needed for the one-shot 614 (for example the providedcontrol signal may be optical while the one-shot 614 may requirepersistent-state control signal 604 to be electrical), a conversionoperation (not pictured) may be provided in order to produce apersistent-state control signal 604 compatible with the input to theone-shot 614.

In some circumstances the control signal may be in the form of astate-transition control signal but the valve to be controlled requiresa persistent-state control signal. In this case an additional conversionis required. FIG. 6 c depicts an exemplary realization of thisarrangement. Here an incoming state-transition control signal 603 may beprovided to a flip-flop 613 function that retains the state valueassociated with the received value of the incoming state-transitioncontrol signal 603. The flip-flop 613 function subsequently cannaturally provide a persistent-state signal 623 that may be applied orotherwise provided to a driver 633 which may convert and/or isolate thecontrol signal into power or energy 643 used to maintain the state of acontrollable valve 653. In some embodiments, the persistent-state signal623 itself may be such that it can directly provide power or energy 643to directly maintain the state of a controllable valve 653; in this casethe driver 633 may be omitted.

Similarly, in other circumstances the control signal may be in the formof a persistent-state control signal but the valve to be controlledrequires a state-transition control signal. In this case an additionalconversion is required. FIG. 6 d depicts an exemplary realization ofthis. Here an incoming persistent-state control signal 604 may beprovided to a one-shot 614 function that creates a transient signalreflecting the change in the incoming persistent-state control signal604. The flip-flop 614 function subsequently can naturally provide apersistent-state signal 624 that may be applied provided to a driver 634which may convert and/or isolate the control signal into power or energy644 used to maintain the state of a controllable valve 654. In someembodiments, the state-transition signal 624 itself may be such that itcan directly provide power or energy 644 to directly maintain the stateof a controllable valve 654; in this case the driver 634 may be omitted.

Control Signal Architecture

The control signals 601-604 described in conjunction with FIGS. 6 a-6 dmay come from a variety of sources. Four of many possible examples aredepicted in the exemplary arrangements of FIGS. 7 a-7 d. FIG. 7 adepicts a first arrangement for providing control signals to acollection of k controllable valves 751.1-751.k. As may or may not beneeded or advantageous in various implementations, one or more of thesignals applied to controllable valves 750.1-750.k may be provided byconverters 710.1-710.k and/or drivers 730.1-730.k to process incomingcontrol signals 700.1-700.k in manners such as those described above inconjunction with FIGS. 6 a-6 d. In the example of FIG. 7 a, the controlsignals 700.1-700.k are provided directly by a controlling processor761. The controlling processor 761 may be part of the larger associatedsystem comprising the Multi-channel Chemical Transport Bus, or thecontrolling processor 761 may be external to the larger associatedsystem, or controlling processor 761 may itself be considered and/orimplemented as part of the Multi-channel Chemical Transport Bus.

FIG. 7 b depicts a second exemplary arrangement for providing controlsignals to a collection of k controllable valves. As described above inrelation to FIG. 7 a, one or more of the signals applied to controllablevalves may be provided by converters and/or drivers to process incomingcontrol signals 700.1-700.k in manners such as those described above inconjunction with FIGS. 6 a-6 d. In the example depicted in FIG. 7 b, thecontrol signals are provided by a demultiplexer 762 that demultiplexesan incoming control signal 772. The demultiplexer 762 may be part of thelarger associated system comprising the Multi-channel Chemical TransportBus, or the demultiplexer 762 may be external to the larger associatedsystem, or demultiplexer 762 may itself be considered and/or implementedas part of the Multi-channel Chemical Transport Bus. This exemplaryarrangement may be advantageous when the control signals provided bydemultiplexer 762 are state-transition signals.

FIG. 7 c depicts a third exemplary arrangement for providing controlsignals to a collection of k controllable valves. As described above inrelation to FIG. 7 a, one or more of the signals applied to controllablevalves may be provided by converters and/or drivers to process incomingcontrol signals 700.1-700.k in manners such as those described above inconjunction with FIGS. 6 a-6 d. In the example depicted in FIG. 7 c, thecontrol signals are provided by an addressable latch 763 responsive toan incoming control signal 773. The addressable latch 763 may be part ofthe larger associated system comprising the Multi-channel ChemicalTransport Bus, or the addressable latch 763 may be external to thelarger associated system, or addressable latch 763 may itself beconsidered and/or implemented as part of the Multi-channel ChemicalTransport Bus. This exemplary arrangement may be advantageous when thecontrol signals provided by addressable latch 763 are persistent-statesignals.

FIG. 7 d depicts a fourth exemplary arrangement for providing controlsignals to a collection of k controllable valves. As described above inrelation to FIG. 7 a, one or more of the signals applied to controllablevalves may be provided by converters and/or drivers to process incomingcontrol signals 700.1-700.k in a manner such as that described above inconjunction with FIGS. 6 a-6 d. In the example depicted in FIG. 7 d, thecontrol signals are provided by local controlling processor 764responsive to an incoming control signal and/or other communications774. The local controlling processor 764 may be part of the largerassociated system comprising the Multi-channel Chemical Transport Bus,or the local controlling processor 764 may be external to the largerassociated system, or local controlling processor 764 may itself beconsidered and/or implemented as part of the Multi-channel ChemicalTransport Bus.

FIG. 7 e shows an exemplary arrangement wherein two or more instances780.1-780.p of the control signal arrangements of FIGS. 7 b-7 d may beincorporated into a larger-scale control signal architecture. Each ofthe two or more instances 780.1-780.p may be any of the exemplarycontrol signal arrangements of FIGS. 7 b-7 d, so that the collection780.1-780.p may be all of the same type or of mixed type. Each instanceincludes its own uniquely associated local control signal source760.1-760.p, which may be demultiplexer, addressable latch, localprocessor, or other controllable signal source. Each local controlsignal source 760.1-760.p is respectively provided with a uniquelyassociated communications path 770.1-770.p that interfaces with a sharedsignal bus 795.0. In the arrangement of FIG. 7 e, the shared signal bus795.0 also connects with a control processor 790.0 via communicationspath 770.1. The control processor 790.0 can thus provide controllingcommunications to each of the local control signal sources 760.1-760.p.The shared signal bus 795.0 and associated interconnections may alsofacilitate additional related and unrelated communications among thecontrolling processor 790.0 and/or the local control signal sources760.1-760.p.

FIG. 7 f shows an exemplary variation of the arrangement of FIG. 7 ewherein the control processor 790.0 of FIG. 7 e is replaced by a localcontrolling processor 791.0 that is also provided with an externalcommunications path 799.0. The external communications path 799.0 mayconnect with another peer, superior, or subordinate processor, directlyor via another communications bus.

FIG. 7 g shows an exemplary variation of the arrangement of FIG. 7 ewherein the control processor 790.0 of FIG. 7 e is omitted. In such anarrangement, each of the local control signal sources 760.1-760.p maycommunicate amongst themselves. This arrangement is at least applicableto arrangements wherein the instances 780.1-780.p comprise localcontrolling processors (such as the case depicted in the example of FIG.7 d).

FIG. 7 h shows an exemplary variation of the arrangements of FIG. 7 fand FIG. 7 g wherein the local controlling processor 791.0 of FIG. 7 eis replaced by a bus interface 792.0 that is also provided with anexternal communications path 797.0. The external communications path797.0 may connect with another peer, superior, or subordinate processor,directly or via another communications bus.

FIG. 7 i shows an exemplary arrangement wherein q instances (q at least2) of the arrangement of FIG. 7 f are in turn each connected via theirrespective communications paths 799.1-799.q with an additional sharedsignal bus 799. This additional shared signal bus 799 is also connectedto a global control processor 790 via communications path 796. Thisglobal control processor 790 can thus provide controlling communicationsto each of the local controlling processors 790.1-790.p. The sharedsignal bus 799 and associated interconnections may also facilitateadditional related and unrelated communications among the global controlprocessor 790 and/or the local control signal sources 769.1-790.p. Insome embodiments, the shared signal bus 799 may also provide controlsignals to and/or exchange other communications 785 with othercontrolled devices and/or processors.

FIG. 7 j shows an exemplary variation on the arrangement of FIG. 7 iwherein the global control processor 790 is replaced by a globalcontrolling processor 793 that is also provided with an externalcommunications path 798. The external communications path 798 mayconnect with another peer, superior, or subordinate processor, directlyor via another communications bus.

FIG. 7 k shows an exemplary variation of the arrangement of FIG. 7 jwherein the global controlling processor 793 is replaced by a businterface 794 that is also provided with an external communications path798. The external communications path 798 may connect with another peer,superior, or subordinate processor, directly or via anothercommunications bus.

Exemplary Embodiments and Capabilities of a Controllable Open-SystemMulti-Channel Chemical Transport Bus

The exemplary embodiment of a Multi-channel Chemical Transport Busdepicted in FIG. 4 has been shown to implement varioussoftware-controllable closed systems such as those depicted in FIGS. 2a, 2 b, and 3 a and various closed system configurations such as thosedepicted in FIGS. 5 a-5 c. The exemplary embodiment of a Multi-channelChemical Transport Bus depicted in FIG. 4 can also be adapted toimplement open systems such as those depicted in FIGS. 1, 2, 3 b, and 3c.

FIG. 8 a shows an exemplary open system embodiment employing the samebasic types of components and architectures as that of the closed systemembodiment of FIG. 4 but adding additional external paths 801 to the buslines 410.1-410.n. This adaptation can implement open systems such asthose depicted in FIGS. 1, 2, 3 b, and 3 c by simply servicing variousflow directions. The external paths 801 can be used to provide inputsand outputs of chemical substances to and from the larger associatedsystem. Note it is also possible to use ports that would otherwiseconnect with system-internal devices as inputs and outputs. In somecases this may be advantageous, but typically incurs a complexitypenalty in that more valves may be required as compared to using theexternal paths 802. The inputs and outputs may be chemical substancesassociated with the fundamental purpose of the larger associated systemwith respect to an application, and may also provide means for clearingand cleaning at least the Multi-channel Chemical Transport Bus betweenat least some operations. Clearing and cleaning at least theMulti-channel Chemical Transport Bus is considered further in asubsequent section.

FIG. 8 b shows a variation of FIG. 8 a where only some of the bus lines410.1-410.n of FIG. 4 are provided with external paths 802 while otherpaths 812 of the bus lines 410.1-410.n of FIG. 4 have no such externalpaths. In such an arrangement, the external paths 802 can be used toprovide inputs and outputs of chemical substances to and from the largerassociated system and may also provide means for clearing and cleaning.The internal-only bus lines 812 may be used for interconnections ofdevices. Note it is also possible to use ports that would otherwiseconnect with system-internal devices as inputs and outputs. In somecases this may be advantageous, but typically incurs a complexitypenalty in that more valves may be required as compared to using theexternal paths 802.

Transport and Pressure Equalization Issues in the Multi-Channel ChemicalTransport Bus

In order for flows to occur there typically must be pressure differencesor gradients within the larger associated system and/or any externalconnections outside the larger associated system. In some embodiments,implementations, and applications these pressure differences orgradients may provide the means for propelling transported substancesand materials within the Multi-channel Chemical Transport Bus, and assuch may be created or modulated by pumps, valves, chemical reactions,or other means. In other embodiments, implementations, and applicationsthe propelling transported substances and materials within theMulti-channel Chemical Transport Bus may involve other transportprocesses, such as microchannel osmosis or electrokinetic flow. In thesecircumstances pressure differences or gradients within the largerassociated system and/or any external connections are created as aresult of transport processes.

In either case, various embodiments provide for pressure equalizationand/or venting required in order for the flows of liquids and gasses tooccur. In some embodiments, implementations, and applications pressureequalization and/or venting may be accomplished by additional ports andpaths on the Multi-channel Chemical Transport Bus, or on a separateMulti-channel Chemical Transport Bus devoted to pressure equalizationand/or venting functions, or a combination of these, as well as othermeans.

Localization and Contamination Issues in Multi-Channel ChemicalTransport Bus Design

One operational concern in the chemical bus arrangements depicted inFIGS. 4, 8 a and 8 b is contamination and waste resulting from residuesand remnants of previous flows. For example, consider the arrangement inFIG. 4 as may be used in implementing FIGS. 2 a, 2 b, and 3 a. FIG. 9 adepicts an exemplary situation involving incoming 951 and outgoing 952flow routed 953 through open valves 951.1 and 952.1 through a connectingbus line of the Multi-channel Chemical Transport Bus embodiment depictedin FIG. 4. However, due to seepage, splattering osmosis, pressuregradients, and/or other processes, chemical substances will typically,at least to some degree, leak at either end of the routed flow 953 asshown by the dashed lines 963.1 and 963.2, as well as leaching into thevestibules of the paths 961.2-961.n, 962.2-962.n linking to otherproximate valves 951.2-951.n, 952.2-952.n.

The matter of leaching into the vestibules of the paths linking to otherproximate valves will be considered later. Here, FIG. 9 b illustratesthe introduction of additional on/off valves 871, 872 to localizeleakage and leeching 863.1, 863.2 illustrated in FIG. 9 a to a smallerspan 873. Of course these two additional on/off valves 871, 872 areessentially only an effective localizing value for the situationdepicted in FIG. 9 a. However, the approach illustrated in FIG. 9 b canbe generalized throughout a Multi-channel Chemical Transport Bus byintroducing on/off valves as proximate as possible on either side ofeach “T” junction of the bus lines as shown in FIG. 9 c. These will bereferred to herein as localization valves. In some implementations andembodiments, such as a LoC device, the resultant large number oflocalization valves each may be “relatively cheap” in that they arereadily rendered via sequences of photolithography or othermass-automated process. In other systems, the resultant large number ofrelatively more expensive valves may still be cost justified by othereconomic considerations of the resulting system.

Closer inspection of FIG. 9 c shows that systematic repetitive placementof the numerous localization valves throughout the bus lines to localizeleaking and leeching reveals functionally redundant valves at either endof each bus line. FIG. 9 d shows a simplification of the arrangement ofFIG. 9 c where functionally redundant valves at either end of each busline have been omitted.

FIGS. 10 a-10 d show exemplary usage of the arrangement of FIG. 9 d toprovide a sequence of different flow paths. As is clear to one skilledin the art, the arrangement of FIG. 9 d can also support multiplesimultaneous flows. However, the sequence depicted in FIGS. 10 a-10 dalso are sufficient to illustrate that a number of the valves canpotentially be reused in the transport of typically different chemicalsubstances. This raises the issue of single-purpose use and the issue ofclearing and cleaning of the Multi-channel Chemical Transport Busbetween at least some operations.

In particular, FIG. 10 a shows a first exemplary flow between Device 2and Device 3 employing open valves 1008, 1003, 1004, 1005, and 1007.Next, FIG. 10 b shows a second exemplary flow between Device 2 andDevice 4 employing open valves 1008, 1003, 1004, 1005 and 1006. Then,FIG. 10 c shows a third exemplary flow between Device 1 and Device 3employing open valves 1001, 1002, 1003, 1004, 1005, and 1007. Finally,FIG. 10 d shows a fourth exemplary flow between Device 1 and Device 2employing open valves 1001, 1002 and 1008.

As can be seen from the exemplary sequence depicted in FIGS. 10 a-10 d,each of valves 1001, 1002, 1003, 1004, 1005, 1007, and 1008 are used atleast twice, however potentially different chemical substances may beexchanged among devices. Thus, typically it is advantageous to provideprovisions to avoid or limit contamination among the potentiallydifferent chemical substances.

In some embodiments and applications, portions of a Multi-channelChemical Transport Bus may be designated for single substance-type use,single-purpose use, or even single-event use. Such embodiments andapplications typically lead to increasing the bus line count n (forexample in FIG. 4) with resulting impacts on complexity. In someapplications or embodiments, software or firmware control of theMulti-channel Chemical Transport Bus may include a predefined resourceallocation strategy to enforce single substance-type use, single-purposeuse, or even single-event use of Multi-channel Chemical Transport Buselements. In other embodiments, software or firmware control of theMulti-channel Chemical Transport Bus may include a dynamicallyresponsive usage-event tagging system providing input to a bus dynamicresource allocation system to enforce single substance-type use,single-purpose use, or even single-event use of Multi-channel ChemicalTransport Bus elements. In yet other embodiments, combinations ofpredefined resource allocation strategy and dynamic resource allocationsystem techniques may be used.

In other embodiments and applications, at least portions of aMulti-channel Chemical Transport Bus embodiment may provide for someform of clearing and cleaning of at least some portions theMulti-channel Chemical Transport Bus between at least some operations toallow buses, valves, and in many cases connected devices to be reusedwith limited contamination.

In yet other embodiments and applications, combinations of clearing andcleaning together with single substance-type use, single-purpose use, oreven single-event use of at least some portions the Multi-channelChemical Transport Bus may be employed. Various embodiments also providefor other methods of facilitating reuse of buses, valves, and in manycases connected devices to be reused with limited contamination as maybe made possible from advances in technology and/or alternate orimproved systems and methods.

With these considerations established, attention is now directed toexemplary methods and systems for clearing and cleaning. In addition tofacilitating reuse of at least some Multi-channel Chemical Transport Buscomponents and/or attached devices in a larger associated system,clearing and cleaning may also be used to remove potentially dangerous,toxic, or contaminating substances prior to the recycling, disposal, ordestruction of a Multi-channel Chemical Transport Bus or largerassociated system at end-of-life.

Clearing and Cleaning Architectures

Clearing and cleaning of Multi-channel Chemical Transport Bus componentsand potentially of attached devices typically involves the followingsteps:

-   -   1. Evacuating bulk remnant substances left within elements after        a desired flow is completed;    -   2. Purging residual traces of substances left within elements        remaining after evacuating bulk remnants;    -   3. Any additional steps as may be needed to remove bulk remnant        and residual traces of materials used in the above steps.

A few examples are considered below.

-   -   As a first example, if the completed desired flow was of a        substance sufficiently volatile in air or other gases, the above        may be realized by simply applying a flow of the appropriately        chosen air of gas. At first a gas flow will push through the        bulk remnant substances left within elements, initially as a        flow and then as a sputter. Here, the role and value of the        aforementioned localization valves is quite apparent. In this        mode the flowing gas acts as a clearing gas. Then the flow of        the same or different gas is used to facilitate the evaporation        of residual traces of substances left within elements. In this        mode the flowing gas acts as a cleaning gas. Should the cleaning        gas be such that it be undesirable to leave within the flow path        prior to the next use of the Multi-channel Chemical Transport        Bus components and/or attached devices, the flow path may be        cleared of cleaning gas by flow-based replacement by an ambience        gas or by a vacuum operation. In some situations, the cleaning        gas may comprise a fixed mixture, variable mixture, or sequence        of different gasses.    -   As a second example, a clearing gas is used to push through the        bulk remnant substances left within elements. Then one or more        volatile liquid solvents flow through the path in order to        dissolve residual traces of substances left within elements. In        this mode the flowing liquid solvent(s) act(s) as a cleaning        solvent, or more generally a cleaning liquid. Next a clearing        gas flow will push through the bulk remnant substances left        within elements, initially as a flow and then as a sputter. Then        flow of one or more cleaning gasses is used to facilitate the        evaporation of residual traces of substances left within        elements. Should the cleaning gas be such that it be undesirable        to leave within the flow path prior to the next use of the        Multi-channel Chemical Transport Bus components and/or attached        devices, the flow path may be cleared of cleaning gas by        flow-based replacement by an ambience gas or by a vacuum        operation. In some situations, the cleaning gas may comprise a        fixed mixture, variable mixture, or sequence of different        gasses.    -   As a third example, one or more liquids may be used to first        push through the bulk remnant substances left within elements        and then dissolve residual traces of substances left within        elements. In this mode the flowing liquid acts as a clearing        liquid. Next one or more volatile liquid cleaning solvents flow        through the path in order to dissolve residual traces of        substances left within elements. Then a clearing gas flow will        push through the bulk remnant substances left within elements,        initially as a flow and then as a sputter. Then flow of one or        more cleaning gasses is used to facilitate the evaporation of        residual traces of substances left within elements. Should the        cleaning gas be such that it is undesirable to leave within the        flow path prior to the next use of the Multi-channel Chemical        Transport Bus components and/or attached devices, the flow path        may be cleared of cleaning gas by flow-based replacement by an        ambience gas or by a vacuum operation. In some situations, the        cleaning gas may include a fixed mixture, variable mixture, or        sequence of different gasses.    -   As a fourth example, one or more liquid solvents may be used to        first push through the bulk remnant substances left within        elements and then dissolve residual traces of substances left        within elements. In this mode the flowing liquid solvent(s)        act(s) as both a clearing liquid and a cleaning solvent. Then a        clearing gas flow will push through the bulk remnant substances        left within elements, initially as a flow and then as a sputter.        Then flow of one or more cleaning gasses is used to facilitate        the evaporation of residual traces of substances left within        elements. Should the cleaning gas be such that it be undesirable        to leave within the flow path prior to the next use of the        Multi-channel Chemical Transport Bus components and/or attached        devices, the flow path may be cleared of cleaning gas by        flow-based replacement by an ambience gas or by a vacuum        operation. In some situations, the cleaning gas may include a        fixed mixture, variable mixture, or sequence of different        gasses.

Evacuated remnant substances, clearing, and/or cleaning materials may becollected for recycle, recovery, and/or disposal. The collecting mayoccur within the larger associated system, outside the larger associatedsystem, or in selective or sequenced combination. In variousembodiments, any recycle, recovery, and/or disposal may occur within thelarger associated system, outside the larger associated system, our inselective or sequenced combination.

Numerous variations of these clearing and cleaning substances andtechniques are clear to one skilled in the art, and are provided for byassorted embodiments of the present invention. For example, in someapplications ambient liquids may be used in place of ambient gas orvacuum. In some embodiments, aerosols may be used in place of clearingand/or cleaning liquids or gases. Additionally, other types ofsubstances and applications may involve other types of clearing andcleaning techniques as is clear to one skilled in the art.

The clearing and cleaning techniques described herein can be implementedin a wide variety of ways using existing ports and paths withembodiments of the Multi-channel Chemical Transport Bus componentsand/or attached devices as described herein. In this approach, typicallysome internal or external sources provide cleaning and clearingmaterials (liquids, gases, aerosols, etc.) and some internal or externalsinks are used to provide exit means for evacuated substances andcleaning materials.

Additionally, special provisions can be included for implementingclearing and cleaning features and operations. Two simple examples aredescribed below, and further examples will be described in the contextof other Multi-channel Chemical Transport Bus embodiments andimplementations in subsequent material.

As a first example of a special provision for clearing and cleaning,FIG. 11 a depicts an extra dedicated bus line linked to each device portwith an individually associated “SPDT” (“single-pole double-throw”, alsoknown as “3-way”) valve for injecting clearing or cleaning material(s)into an attached device. FIG. 11 b shows exemplary flow (signified bythe bolded arrowed path) of a clearing or cleaning material through thisdedicated bus line, traveling through the SPDT valve, and directed tothe attached device.

As a second example of a special provision for clearing and cleaning,FIG. 12 a depicts a similar extra dedicated bus line linked to eachdevice port with an individually associated SPDT valve for evacuatingremnant substances, clearing, and/or cleaning material(s) from anattached device. FIG. 12 b shows exemplary flow (signified by the boldedarrowed path) of an evacuating substance and/or material through thisdedicated bus line, traveling through the SPDT valve, and directed tothe attached device.

Incorporation of Flow and Other Sensors

In some embodiments, it may be advantageous to introduce or incorporateone or more sensors at various places within a Multi-channel ChemicalTransport Bus, for example between each adjacent bus line tap. Thesesensors may be of one or more types, for example presence-sensors,flow-sensors, pressure-sensors, temperature-sensors,conductivity-sensors, turbidity-sensors, optical-sensors (i.e.,transmission, absorption, polarization-rotation, etc.), ion-sensors,affinity-sensors, etc. as may be useful, desired, or advantageous in theoperation of a Multi-channel Chemical Transport Bus and/or largerassociated system. FIG. 13 a illustrates some exemplary placements ofsensors, represented by dashed squares, at various locations along thebus line segments between consecutive taps and on port paths within aMulti-channel Chemical Transport Bus. FIG. 13 b depicts other sensorplacements on either proximate side of a bus line tap. These sensorsmay, for example, serve to detect the presence and/or flow-rate ofsubstances or materials in the depicted locations as may be advantageousor necessary for precise control of measured flows or for higherperformance in clearing and/or cleaning operations.

Short-Duration Transport

Although attention will be directed to alternate embodiments andimplementations of a Multi-channel Chemical Transport Bus, the exampleof FIG. 4 will continue to be used to illustrate one more group ofadditional concepts, namely short-duration transport. For simplicitymany other issues raised and techniques introduced will initially be setaside. However, one skilled in the art will appreciate how the issuesdescribed regarding short-duration transport naturally carry over toother embodiments and implementations of a Multi-channel ChemicalTransport Bus.

FIG. 14 depicts an generalized continuous flow between two devices.Again for simplicity, issues and solutions involving leakage, leeching,localization, clearing, cleaning, etc. are set aside. Such a continuousflow is relevant for most rapid or simply-operated transport of chemicalsubstances through a Multi-channel Chemical Transport Bus. However, inmany cases it may be desirable or advantageous to transport chemicalsubstances or clearing and cleaning materials in considerably smallerquantities that would be involved in the continuous flow depicted inFIG. 14. In this section, the transport of isolated or repeated shortbursts of liquid substances or materials is considered.

As an opening example, FIG. 15 a shows a short-duration flow segment, orburst, of a substance or material. In this figure, the burst is in theprocess of being transported from a source device deeper into theMulti-channel Chemical Transport Bus. On either side of theshort-duration flow segment (i.e., burst) of the liquid substance ormaterial is assumed to be ambient gas, a vacuum condition, a propellinggas, or in some circumstances a gas that may be used together with theliquid substance or material. Typically, however, any gases between eachburst do not affect the substance or material being transported. FIG. 15b shows the exemplary liquid substance or material presented in FIG. 15a traveling through a bus segment of the Multi-channel ChemicalTransport Bus, while FIG. 15 c shows the exemplary liquid substance ormaterial in the last stages of transport to a sink device.

Throughout the burst transport depicted in FIGS. 15 a-15 c the twovalves depicted as open circles are opened throughout. In anotherembodiment, when the exemplary liquid substance or material issufficiently localized within the bus segment, the valve associated withthe source port may be closed and a propellant gas may be applied fromanother source port, as depicted in FIGS. 15 d-15 e which replace FIGS.15 b-15 c. In a similar fashion, as shown in FIG. 15 f, a vacuum can beapplied from another sink port rather than by the full transport pathitself (as in the case in FIG. 15 a).

FIG. 16 a shows an exemplary closely-spaced sequence of bursts of thesame liquid substance or material. Between each burst are gases or otherneutral substances that do not affect the substance or material beingtransported. In one step of this exemplary sequence, the two valvesdepicted as open circles are opened throughout the full interval of theburst sequence. However, more sophisticated operations are alsopossible. For example, FIG. 16 b depicts an alternate next step of thisexemplary sequence where the destination port valve on the bus closes,allowing the flow to be directed to another destination via a now openedvalve on the bus line. Meanwhile, a burst segment destined for theoriginal destination but remaining in-line can be delivered byintroducing a propelling gas from another source port via another busline and associated open valves. By carefully choreographed timing,perhaps advantageously aided by the above noted sensors, the arrangementof FIG. 16 b can be used to provide precisely-time pre-staged deliveriesto multiple destination ports.

FIG. 17 shows stuttered bursts of a liquid substance or material beingtransported. This technique can be useful in various ways, for examplein operations such as titrations, or to impose pressure impacts inclearing and cleaning, or when the propelling gas is to be mixedtogether with the liquid substance or material, etc.

Next some of the concepts just introduced and variations of them will beviewed in the context of the operation of localization valves within thebus lines of a Multi-channel Chemical Transport Bus. As an example, FIG.18 a shows a burst of liquid substance or material, represented as Burst#1, introduced to the Multi-channel Chemical Transport Bus by Device 2.To direct the flow from Device 2 to Device 4, valves 1808, 1803, 1804,1805 and 1806 are opened.

FIG. 18 b shows Burst #1 as it continues to move into the top bus line.In this figure we can observe that Burst #1 has already passed throughvalves 1808 and 1803 and these valves have been closed, trapping Burst#1 completely within a localized segment of the bus line. The valveswhere Burst #1 has not yet passed through remain open. Meanwhile, justbefore, a second burst, Burst #2, has been introduced by Device 2.Because of the closed valves, Burst #1 is also completely trapped in alocalized segment.

Valves 1801-1803 can then open, allowing Device 1 to provide venting orpropelling gas to allow Burst #1 to move at least approximately into theposition depicted in FIG. 18 c. Valves 1801-1803 then close prior to thetime captured by FIG. 18 c. In one embodiment, Device 1 propels Burst #1with a pressure pulse sufficient to propagate it into Device m evenafter valve 1804 closes. In another embodiment, valve 1807 may openallowing Device m−1 to provide venting or propelling gas to allow Burst#1 to propagate it into Device m after valve 1804 closes. Additionallyin FIG. 18 c, valves 1808, 1802 and 1801 have been opened leading Burst#2 to Device 1.

FIG. 18 d shows Burst #1 now about to arrive at destination Device 4,leveraging momentum or extra imparted back pressure, despite all valvestraversed in its travel thus far are now closed. FIG. 18 d also showsthe Burst #2 having already traversed several valves that are nowclosed, confining it. Valve 1801 remains open.

FIG. 18 e shows Burst #2 arriving at its destination, allowed or drivento travel by venting or propelling gas provided by Device m−1 via nowopened valves 1801, 1802, 1803, 1804, and 1807.

Further Alternate Embodiments of a Multi-Channel Chemical Transport Bus

Next, a number of exemplary alternate embodiments of a Multi-channelChemical Transport Bus are provided, some leveraging aforementionedsingle-pole single-throw (“SPDT”) valves.

FIG. 19 a shows a device port bus column where the on/off valves havebeen replaced with SPDT valves. This valve cascade arrangement allowspassage or isolation when valve is turned on/off. The top portion of thedevice port bus column could connect to another valve, or to portions ofa dedicated clearing and/or cleaning architecture. FIG. 19 b shows anexemplary gated path through the port bus column of FIG. 19 a,illustrating how the SPDT valves provide enhanced isolation againstcontamination as compared to the port bus column employed in FIG. 4.

FIG. 19 c shows the arrangement in FIG. 19 a as now being constructed inthe opposite manner. In this arrangement the valve cascade can be usedas a distribution valve readily amenable to clearing and cleaning. Forexample, the downward outlet at the bottom valve would be used as anevacuating drain. FIG. 19 d shows an exemplary gated path through thearrangement of FIG. 19 c.

FIG. 20 a depicts an exemplary alternate realization of a Multi-channelChemical Transport Bus employing the valve cascade arrangement of FIG.19 a as the device port bus column. FIG. 20 b depicts an exemplaryalternate realization of a Multi-channel Chemical Transport Busemploying the valve cascade arrangement of FIG. 19 c as the device portbus column.

FIG. 21 a depicts an exemplary expanded arrangement where each port isprovided with a SDPT valve, the SDPT valve selecting between what wouldotherwise be two separate ports of the same Multi-channel ChemicalTransport Bus. Such an arrangement can be useful for rapid delivery viapre-staged transport, or to isolate when contamination, or as aredundant backup in case of failure.

A SDPT valve may be viewed as a 2-port mutually-exclusive selection ordistribution valve. Additionally, there are many widely knownimplementations at various physical scales (including scales relevant toLoC systems) of k-port mutually-exclusive selection or distributionvalves wherein k>2 (for example, employing a rotary element). FIG. 21 bshows a corresponding adaptation of FIG. 21 a where the SDPT valves havebeen replaced with k-port mutually-exclusive selection or distributionvalves where each of the k ports selects among what would otherwise be kseparate ports of the same Multi-channel Chemical Transport Bus.

FIG. 22 a shows the arrangement of FIG. 21 a where the two ports of theSPDT valve are connected to what would otherwise be the output ports oftwo separate Multi-channel Chemical Transport Busses. This arrangementwould be used to cut down the number of valves needed in somelarge-scale system, and may also be used to prevent or localizecontaminations.

Similarly, FIG. 22 b shows an arrangement of FIG. 21 b where each of thek ports connected to what would otherwise be the output ports of kseparate Multi-channel Chemical Transport Busses. FIG. 23 shows anexemplary implementation of FIG. 22 b using only on/off valves.

Clos, Banyan, and Related Routing Architectures

In communications systems, it is known that the now-classical Clos,Banyan, and other related switch architectures can be used under variousconditions to reduce the switch-element count. An embodiment of theinvention provides for the topology of Clos, Banyan, and other relatedswitch architectures to be adapted for use in implementing aMulti-channel Chemical Transport Busses to reduce valve element countand/or provide specific interface, layout, fabrication, redundancy orperformance features. For instance, the system may be configured toinclude a Clos network topology that is adapted to chemical flow paths

While the invention has been described in detail with reference todisclosed embodiments, various modifications within the scope of theinvention will be apparent to those of ordinary skill in thistechnological field. It is to be appreciated that features describedwith respect to one embodiment typically may be applied to otherembodiments. Therefore, the invention properly is to be construed withreference to the claims.

1. A system for implementing an electrically-operated multi-channelchemical transport bus, the system comprising: a plurality of chemicalflow ports, each chemical flow port connected to at least one associatedfirst electrically-operated valve and further in chemical flowcommunication with at least one associated second electrically-operatedvalve; a first chemical flow bus line connecting with each firstelectrically-operated valves respectfully associated with each chemicalflow port from the plurality of chemical flow ports, each connectionmade at an associated tap in the first chemical flow bus line; a secondchemical flow bus line connecting with each second electrically-operatedvalves respectfully associated with each chemical flow port from theplurality of chemical flow ports, each connection made at an associatedtap in the second chemical flow bus line; at least one sensor associatedwith at least one of the first chemical flow bus line, and a controllerfor selectively controlling the operation of each of theelectrically-operated valves, the controller controlling communicationswith each of the electrically-operated valves, wherein the controllerfurther controls the electrically-operated valves to: initially preventchemical flows between a first and second chemical flow ports of theplurality of chemical flow ports, transport chemical flows between afirst and second chemical flow ports of the plurality of chemical flowports; and again prevent chemical flows between a first and secondchemical flow ports of the plurality of chemical flow ports.
 2. Thesystem of claim 1 wherein the at least one associated firstelectrically-operated valve and at least one associated secondelectrically-operated valve are single-pole double-throw valves.
 3. Thesystem of claim 1 wherein the system permits chemical flows between athird and fourth chemical flow ports of the plurality of chemical flowports during the time wherein the chemical flow occurs between a firstand second chemical flow ports of the plurality of chemical flow ports.4. The system of claim 1 wherein the controller receives control signalsfrom a control signal source.
 5. The system of claim 1 wherein thecontroller provides a clearing mode to clear remnants of an earlierchemical flow.
 6. The system of claim 1 wherein the controller providesa clearing mode to clean residuals of an earlier chemical flow.
 7. Thesystem of claim 1 wherein the system enforces for single-purpose use ofat least a portion of a chemical flow bus line.
 8. The system of claim 1wherein the system enforces for single-event use of at least a portionof a chemical flow bus line.
 9. The system of claim 1 wherein the systemcomprises a Clos network topology adapted to chemical flow paths. 10.The system of claim 1 wherein the system comprises a Banyan networktopology adapted to chemical flow paths.
 11. The system of claim 1, thefirst chemical flow bus line further comprising a first pair ofadditional electrically-operated valves, one on either side of at leastone tap of the associated tap in the first chemical flow bus line. 12.The system of claim 11, wherein the transported chemical flow does notextend into the chemical flow bus line beyond at least the first pair ofadditional valves.
 13. The system of claim 1 wherein the at least onesensor is a presence sensor.
 14. The system of claim 1 wherein the atleast one sensor is a flow sensor.
 15. The system of claim 1 wherein theat least one sensor is a pressure sensor.
 16. The system of claim 1wherein the at least one sensor is a temperature sensor.
 17. The systemof claim 1 wherein the at least one sensor is a conductivity sensor. 18.The system of claim 1 wherein the at least one sensor is an opticalsensor.
 19. The system of claim 1 wherein the at least one sensor is anion sensor.
 20. The system of claim 1 wherein the at least one sensor isan affinity sensor